JP2564943Y2 - Optical head device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head device in an optical disk recording / reproducing device for optically reproducing or recording / reproducing information, and more particularly to an optical head device in which dust-proof and dew-proofing of a separation type optical head are thoroughly performed. About.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view of a conventional optical head, and FIG. 4 is a perspective view of a conventional separation type optical head. In FIG. 3, unlike the separation type optical head, since the optical system and the lens actuator 58 system are configured in one housing, the conventional lens system which cannot exhibit sufficient functions when it comes in contact with dust, dust or dew is an objective lens. It was only 56. However, no countermeasures have been taken against the objective lens 56, and recording and reproduction cannot be performed if dust, dust, dew, or the like adheres.
In the case of the separation type head, the optical system 69 also required measures. In other words, in the optical head device of the optical disk, the lens 60 and the magnetic circuits 65 and 66 are provided with the cover members, but between the objective lens and the disk are provided with cutout holes for focusing and tracking of the lens. Therefore, it has not been practiced to cover the notched hole with glass for dust prevention and dew condensation because of the small size of the hole, resulting in high cost in the production of glass. Further, even if the notch hole is formed into a cover glass or provided with a cleaning mechanism, the cleaning mechanism needs to be ultra-miniaturized, which also increases the cost. Therefore, none of the above measures has been taken.

[0003]

Among the configurations of the conventional optical head and the separation type optical head, in particular, in the case of the separation type optical head, the light beam exits the fixed optical section 69 and then moves to the movable section 6.
Since the light passes through the mere internal space of the disk drive without any covering up to the rising mirror of No. 8, the dust and dirt from this part are affected by the optical components, so that sufficient performance cannot be exhibited and signal detection cannot be performed. There was a risk that the reliability of the device would decrease.
In addition, taking measures to prevent dust and dew on this part with the above-described conventional configuration results in an increase in the size of the entire apparatus, and the like.
This was practically impossible because of the great loss of commercial value. In Japanese Utility Model Laid-Open No. 3-28530, "Pickup of Optical Disc Player", an objective lens provided in the pickup of the optical disc player is covered with a cap material.
An optical head device is disclosed in which an objective lens operates in an exposed state so that dust does not adhere. However, this is related to an optical head device in which the entire optical system from the laser diode to the objective lens is housed in the case, and is configured to guide the entire case along the guide bar in the scanning direction. Assuming that the present invention is applied to a separation type optical head device in which light passing through the objective lens is extracted to the outside of the case, if only the upper part of the objective lens is covered with the cap material, the movable optical system and the fixed optical system are included. The closed structure could not be completed and had various barriers. In addition, when dust adheres to the cap material that covers the light transmission window passing through the objective lens, or when the cap material does not transmit light due to condensation or the like, measures are taken to eliminate such dust and dew condensation. Since the dust does not adhere to the objective lens,
There is a problem that the recording / reproducing quality is seriously affected. Furthermore, the actual opening Hei 4-7661
No. 4 "Optical recording / reproducing apparatus" discloses an optical head device in which an exposure opening of an objective lens is covered with transparent glass over a moving range of an optical head and a wiper member for cleaning the transparent glass is provided. ing. This relates to an optical head having a configuration in which an entire optical system from a laser diode to an objective lens is housed in a case, and the entire case is guided in a scanning direction along a guide bar. Moreover, since the transparent glass is fixed to the device body side,
Although it covers the aperture window for the objective lens of the case, it is necessary to seek the optical head while sliding the upper surface of the case against the lower surface of the transparent glass, and it is said that there is no entry of dust from the sliding contact portion. There is a problem that the objective lens cannot be completely sealed inside the case without being cut. In addition, the cleaning brush that swings around the fulcrum to clean the transparent glass is located on the opposite side of the objective lens from the spindle, so the driving force of the spindle motor is used to swing the cleaning brush. However, even if it is used daringly, there is a problem that the configuration of the transmission mechanism for transmitting the motor power to the cleaning brush becomes very complicated. Furthermore, Japanese Patent Application Laid-Open No.
203434 No. "Optical head with separate actuator"
Is the laser light entrance window of the movable optical system (actuator section)
And the laser light emission window of the fixed optical system (main body fixing part)
Optical head covered with a transparent plate that can transmit the light is disclosed
Have been. However, this does not penetrate into the parallel beam.
Since a cover made of a bright plate is inserted, this cover
Coma and astigmatism are likely to occur due to
With the problem of lack of precision of the minute spots to be formed
Was something. In addition, the fixed optical system and the movable optical system are linked.
Connecting bellows provide resistance to movement of the movable optical system
Therefore, high-speed access can be achieved even though the optical system is separated.
There was a problem that there was no. In addition,
No. 59-14149 “Optical information recording / reproducing device” includes:
Provide a transparent lid at the end of the actuator,
Equipment designed to prevent dust or moisture from entering the interior
An arrangement is disclosed. However, this is optical
Since the entire system is covered with a cover, it can be used with a fixed optical system.
High-speed access such as a separation type that separates the moving optical system is not
It is possible to cover the entire optical system with a cover.
It is said that a moisture absorbent is built in to prevent
Hygroscopic agent that has lost its moisture absorption effect
Replacement is not easy, and the effect of preventing condensation for a long time is maintained.
It had problems such as being unable to prove. Also, JP
No. 62-34340 "Optical head" has an objective lens
Transparent plastic is provided on the front side of the
Optical head with improved dust-proofing
Have been. However, this optical head is also a separate type
Because it is not a configuration, it is not suitable for high-speed access,
In addition, a cleaning mechanism for cleaning the translucent plastic
Storage for long-term stability of optical properties
Had difficulties, etc. In addition,
No.61-83119 "Optical information recording / reproducing device"
Covers the optical pickup and the condensation detection means with a transparent member.
An apparatus configured as such is disclosed. However, this
Is also a non-separable configuration, so fast access
Cleaning machine that is not suitable for
No built-in structure allows long-term safety of optical characteristics
It had problems such as difficulty in maintaining the constant. Ma
In addition, the actual optical system is
Provide a glass plate on the front side of the lens and seal the entire optical system
Devices to protect against dust and moisture are disclosed.
You. However, this one moves the entire optical system
High speed access is difficult because
And the aberration of the objective lens in consideration of the thickness of the glass plate.
It has a problem that it needs to be corrected.
Was. Also, Japanese Patent Application Laid-Open No. 62-267931, "Optical Head
Cleaning device "is provided at the tip of the optical head
Creeper with a rotary brush that contacts the aperture lens
An apparatus is disclosed. However, this one
Inserts the cleaning device into the optical recording / reproducing device,
Rotate the motor inside the cleaning device to rotate
The brush is rotated, inside the optical recording / reproducing device.
The rotary brush is not permanently installed in the
-The cleaning target of the tally brush is limited to the aperture lens.
Not only the aperture lens but also its surroundings
And other issues. Also,
No. 64-39679 “Condenser lens cleaner cart”
The ridge has an innumerable flock on the surface of the conductive belt.
Cartridge with built-in cleaner belt disclosed
Have been. However, this cartridge is also optically
With a rotary brush permanently installed in the recording / reproducing device
And is formed in an annular shape with a width greater than the moving distance of the optical head.
Although a cleaner belt is used,
It is not possible to clean covers that cover the movement range.
Was a challenge.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and the laser light emitted from a laser diode is transmitted to a disk-shaped recording medium via a fixed optical system fixed on a base. It guides in the scanning direction, irradiates the signal recording surface of the disk-shaped recording medium via the objective lens included in the movable optical system that moves in the scanning direction, and magnetizes it.
In the optical head device for attitude control of the objective lens by mediated, a dust cover for covering said fixed optical system, and the light-transmitting dust cover for covering over said movable optical system in the entire movable range, the magnetic leakage To prevent light transmission
A frame-shaped magnetic shield cover for holding the dust cover;
Arranged on the magnetic shield cover with the swing center supported
Power from the rotary drive source of the disk-shaped recording medium is transmitted.
To clean the surface of the transparent dustproof cover.
And an upper member .
Further, the present invention, the rotation driving source is characterized in that a spindle motor.

[0005]

According to the present invention, a fixed optical system for guiding a laser beam emitted from a laser diode in the scanning direction of a disk-shaped recording medium is covered with a dustproof cover, and a movable optical system that holds the objective lens and moves in the scanning direction. the system was covered with translucent dust cover over its entire movable range, to prevent dust from entering the movable optics, can be guaranteed over a stable recording and reproduction in a long time, also translucent Frame to hold the dustproof cover
Supporting the magnetic Shirudoka bar wiper member swingably
The maximum wiping area for the translucent dustproof cover
To prevent deterioration in reproduction quality due to a decrease in light transmittance.
Can be .

[0006]

FIG. 1 is an exploded perspective view of an embodiment of a separation type optical head according to the present invention, and FIG. 2 is a sectional view showing an example of a cleaning cartridge . The configuration of the separation type optical head includes a fixed optical base 1, an LD (laser diode) 2 as a light source, a fixed optical unit up to the galvanometer mirror 5, a magnetic circuit such as a back yoke 24, a magnet 22, and a carriage 16. And other actuators,
It comprises a spindle motor 14. The light emitted from the fixed optical unit passes through the side yoke 25 and the carriage 16 and is incident on the rising mirror 17 to change the optical path. The light beam is converged by the objective lens 19 and is irradiated on the disk. Focusing for following the surface runout of the disk is performed by detecting an error in the distance between the focal position and the disk with an error detection optical system of the fixed optical unit, and driving the objective lens with an actuator constituted by, for example, a leaf spring. The driving force is obtained from a magnetic circuit including the back yoke 24, the magnet 22, and the like. or,
The tracking control for following the eccentricity of the disk is constituted by a combination in which coarse control is performed by means for moving the entire carriage 16 along the carriage rail 15, and fine control is performed by means for slightly deflecting the beam in the tracking direction by the galvanometer mirror 5. doing. The shield cover 26
The objective lens 19 is for covering a portion necessary to prevent the leakage of magnetism of the magnetic circuit. The objective lens 19 is provided with a cover glass 3 fitted in the rectangular frame-shaped shield cover 30.
Focus on the disk via 0. The cover glass 3
Since 0 has a thickness, x = t (n-1) / n is established when the focal length shift is x, the thickness of the cover glass 30 is t, and the refractive index of the glass is n. As is apparent, by increasing the focal length by the shift x of the focal length, the distance between the disk and the head can be increased. When a countermeasure such as dew condensation is taken by cleaning, the cleaning cartridge 50 uses a spindle motor 54 as a driving source and a cleaning belt 55 through driving gears (1) and 51 and driving gears (2) and 52 provided in the cartridge. Is rotated along the cover glass 30 as shown in FIG. A wiper mechanism 31 driven by the spindle motor 14 is provided on the upper surface of the cover glass 30. The wiper mechanism 31 includes a wiper member 32
Is pivotally supported on the shield cover 26, and the wiper member 32 is usually located at a position off the cover glass 30. The wiper drive unit 33 is separated from the spindle motor 14 and I have. That is, the wiper driving unit 33 is connected to the spindle motor 14 at the time of cleaning, whereby the wiper member 32 swings by receiving the rotational power of the spindle motor 14 and cleans the upper surface of the cover glass 30. As a result, dust, dew, and the like attached to the cover glass 33 are removed.

[0007]

[Effects of the Invention] As described above, according to the present invention,
A fixed optical system that guides the laser light emitted from the laser diode in the scanning direction of the disk-shaped recording medium is covered with a dustproof cover, and a movable optical system that holds the objective lens and moves in the scanning direction is provided over the entire movable range. Therefore, the covering range of the light-transmitting dust-proof cover only needs to cover the entire movable range of the objective lens, and the dust-proof cover that covers the fixed optical system may have a dust-proof function. If a non-light-transmitting cover may be used, the area of the light-transmitting dust-proof cover can be kept to a minimum, and the movable optical system is sealed by the light-transmitting dust-proof cover. Intrusion of dust into optical components can be prevented, stable recording and reproduction can be guaranteed for a long time, the reliability of the optical head can be improved , and the objective lens can be improved.
To prevent external leakage of magnetism that mediates attitude control
Hold the translucent dust-proof cover on the magnetic shield cover
And a disk-shaped record on this magnetic shield cover.
The oscillating wire that receives the power from the rotating drive source of the medium
The light-transmitting dust-proof cover is
Light-transmitting dust-proof covering the movable optical system
Even if the cover becomes dirty or condensed with dust,
The par member swings to clean the surface of the translucent dustproof cover
In this way, the transparency of the dust cover is restored,
Keep the light-proof dust cover in a state where it always performs its original function.
The wiper member holds the light-transmitting dustproof cover.
Transparent because it is supported by a magnetic shield cover
The maximum wiping area for the dust cover can be secured.
In addition, the present invention has excellent effects such as preventing a decrease in reproduction quality due to a decrease in light transmittance . Further , in the present invention, since the rotary drive source is constituted by the spindle motor, the wiper member can be reliably rocked by using the rotational power of the spindle motor which is always driven at the time of recording / reproduction of the disk-shaped recording medium, Further, the light-transmitting dust-proof cover covers the entire movable range of the movable optical system, and the swing fulcrum of the wiper member is naturally disposed near the inner periphery of the disk-shaped recording medium. There is an effect that the power transmission mechanism from the motor to the wiper member can be simply configured.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a separation type optical head according to the present invention.

FIG. 2 is a sectional view illustrating an example of a cleaning cartridge .

FIG. 3 is a perspective view showing an example of a conventional optical head.

FIG. 4 is a perspective view of a conventional separation type head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed optical base 2 LD 3 Collimating lens 4-Body prism 5 Galvano mirror 6 Convex lens 8 Detection lens 9 Reflection mirror 10 PD 11 Optical axis 12 Carriage rail support member 13 Spindle motor attachment part 14 Spindle motor 15 Carriage rail 16 Carriage 17 Start up Mirror 18 Roller bearing 19 Objective lens 19 'Uniaxial actuator 20 Focus coil 21 Carriage coil 22 Magnet 23 Center yoke 24 Back yoke 25 Side yoke 26 Shield cover 27 Dust cover 30 Light-transmitting dust-proof cover (cover glass) 31 Wiper mechanism 32 Wiper Member 33 Wiper drive unit 50 Cleaning cartridge l 51 Drive gear (1) 52 Drive gear (2) 53 Gear drive member 54 Speed Idle motor 55 cleaning belt 56 objective lens 57 linear motor 58 lens actuator 59 speed detector 60 AF actuator 61 optical disk 62 TR actuator 63 linear steel 64 coil 65 yoke 66 magnet 67 rail 68 carriage body 69 optical system body

Claims (2)

(57) [Scope of request for utility model registration] An object included in a movable optical system that guides laser light emitted from a laser diode through a fixed optical system fixed on a base in a scanning direction of a disk-shaped recording medium and moves in the scanning direction. It irradiates the signal recording surface of the disc-shaped recording medium via a lens, of mediating magnetic
In the optical head device for controlling the attitude of the objective lens, a dustproof cover covering the fixed optical system, a translucent dustproof cover covering the movable optical system over the entire movable range thereof, and The light-transmitting dustproof
A frame-shaped magnetic shield cover for holding the bar;
The swing center is supported on the shield cover and the
Power transmitted from the rotational drive source of the disk-shaped recording medium
A wiper that swings and cleans the surface of the translucent dustproof cover
An optical head apparatus characterized by comprising a chromatography member. 2. The rotary drive source is a spindle motor.
2. The optical head device according to claim 1, wherein: